<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="./js/vue.js"></script>
</head>
<body>
	<div id="app">
		<p>{{sum}}</p>
		
	</div>
	<script type="text/javascript">
		new Vue({
			el:"#app",
			data:{
				num_a:3,
				num_b:4,
			},
			computed:{
				//返回值貌似会赋给一个变量
				sum:function(){
					return this.num_a+this.num_b;
				}
			}
		})
	</script>
    
</body>
</html>